This specification relates to search query expansion.
Query expansion refers to modifying a search query received from a user before performing a search. Ideally, the modified search query will yield improved search results compared to the original query. Typical approaches to query expansion include stemming of words, correction of spelling errors, and augmentation of the search query, e.g., using synonyms of words that occur in the original query.
A number of approaches to query expansion using synonyms exist. For example, the synonyms of a word can be identified from an expert-specified thesaurus or a lexical ontology. In some systems synonyms are identified from other search queries that are syntactically similar to the original query. Synonym selection is particularly challenging when a word may have multiple potential synonyms, each with widely varying meanings. For example, in the query “How to ship a box”, the word ‘ship’ can have synonyms e.g., ‘boat’ and ‘send’. Expanding a query with a synonym that is inconsistent with the user's intended meaning can lead to the identification of irrelevant search results. For example, search results related to fishing trawlers are probably not relevant to shipping a box.